Q&A | AREA CODES

The 310 May Face Two Options: Split or Overlay

The state Public Utilities Commission has used conservation methods to ease the telephone problem, but officials say a more drastic solution -- overlaying the whole western Los Angeles County area with an additional code or splitting the area into two codes -- probably will be needed soon.

In the primer that follows, PUC officials outline the history of the 310 area code and explain how past problems were dealt with.

Question: Why were area codes created?

Answer: With the advent of technologies that permitted long-distance dialing, area codes were created in 1947 to replace a complex system of letter codes that were cumbersome, duplicative and unable to accommodate rapidly growing demand for telephones. Initially, California was assigned three area codes: 213 in Southern California, 415 in Northern California and 916 along the eastern flank of the state. Each code was capable of handling about 8 million numbers.

Q: Why are there so many area codes today?

A: As years passed, the demand for additional numbers increased dramatically, in part because of the needs created by computers, fax machines, cellphones and pagers. To satisfy the demand, dozens of area codes were created in California, including the 310, which was carved out of the 213 in 1991.

Demand continued to soar, and by the late 1990s the North American Numbering Plan Administration, a contract consultant set up by the Federal Communications Commission to monitor the supply of telephone numbers, warned that the 310 was again running out.

In 1997, the state Public Utilities Commission split the 310 area, with the Westside and the South Bay retaining the 310 code and Long Beach and the southeastern area of Los Angeles County receiving a new 562 code.

Q: What were the advantages of the split?

A: It essentially doubled the numbers available in the old 310 area, with seven-digit dialing for local calls in each half of the split.

Q: What were the disadvantages of the split?

A: About half the customers in the old 310 area changed codes. For them, stationery, business cards and advertising had to be updated, and friends and customers had to be told about the change. Many cellphones and fax machines had to be reprogrammed. Some customers felt that they were being discriminated against and that the new code -- which did not include the Westside of Los Angeles -- was less prestigious than the old code.

Q: What was done to keep the 310 area from running out of numbers again?

A: Conservation measures were initiated to delay the need for additional splits.

Before these measures were adopted, a carrier would ask the PUC for new numbers and be issued a block of 10,000, even though the carrier might need only 1,000 of them. That would leave 9,000 numbers unused and unavailable. Under new conservation plans, carriers start receiving numbers in blocks of 1,000, instead of 10,000.

Before a carrier could get new numbers, it had to show that it had used up 75% of what it had already been allocated. Numbers were issued sequentially, which meant that each block of 1,000 had to be fully used up before the next block of 1,000 was issued.

Q: Did the conservation efforts solve the problem?

A: Not for long. Within three years, the Numbering Plan Administration announced that the 310 area was again running short of available numbers.

In 1999, the PUC authorized an overlay, in which one or more new codes would be superimposed over the existing 310 area and serve only new phone users.

Although there aren't any yet in California, overlays exist in Colorado, Florida, Georgia, Illinois, Massachusetts, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Oregon, Pennsylvania, Texas and Virginia. In New York City, for example, the old 212 area is overlaid by the 646 and 917 codes.

Q: What are the advantages of overlays?

A: Existing customers retain their numbers. The threat of future splits diminishes because shortages probably will be handled by more overlays.

Q: What are the disadvantages of overlays?

A: Every call within an area requires 11-digit dialing -- 1, the area code and the customer's seven-digit number -- even if the party being called has the same area code. Some customers, such as security-alarm companies, need to make sure their equipment can handle 11-digit calls. Some customers may end up with two different area codes within the same residence or business.